1. Field of the Invention
This invention relates to an electrical motor, more particularly to an electrical motor including a stator formed with stator slots having different depths.
2. Description of the Related Art
Conventional electrical motors for electric fans normally include a rotor and a stator that has a stator core provided with an insulator layer thereon and that is formed with a plurality of identical stator slots and a plurality of identical poles, each of which is disposed between two adjacent ones of the stator slots. The stator is normally provided with a starting winding of an insulated wire wound on selected ones of the poles, and a field winding of insulated wires wound on the remaining poles. Since the depths of the stator slots are identical, and since the lengths of the poles are identical, a relatively great portion of the starting winding unavoidably overlaps the field winding on the stator core. As a consequence, the likelihood that the insulation on the insulated wires of the starting winding and the field winding will be damaged during lamination of the starting winding and the field winding on the stator core by a press is relatively high, which can result in short circuit or failure in controlling rotation of the rotor.